There are many reasons besides asthma that an infant could be wheezing. This article explains some of them and gives a bit of information about treatments that may be used for your baby's wheezing. Also available in Spanish!
Allergy Buyers Club
This is a commercial site selling allergy products, but feel free to just read their helpful article and purchase nothing! Series of questions and answers provides a very thorough article about asthma in infants and how you can cope with it.
If your infant is diagnosed with asthma, you will want to be prepared for handling this chronic condition throughout childhood. This article is a great jumping-off point, including many helpful links to further information on topics.